Code compliance: vent dryer to code

paintdrying, it is actually all over the board. Some places are stating 5 feet for a 90, another is 5-9. The site I linked to which I would trust more, is stating 15 feet for a 90 degree el. I would go with the last, just to be safe. I think that it is the 45 degree el's that are considered 5 feet of pipe run equal to.

i get it now. In that reference it says one 90 degree elbow equals 5 ft, while the 45 degree angle equals 2.5, that is the minimum to meet code. the 15 foot = 1 90degree elbow is just a "study" that was done. seems like they just want you to buy their product. I'm going to stick to minimum.

so it looks like i can get by with 8 foot straight run going up then one 45 degree elbow(equaling to 2.5 ft), a 2 foot straight run following the 45 degree elbow. After the 2 ft straight run follows another 45 elbow (2.5 ft) into a 7 ft straight run going outside.

8+2.5+2+2.5+7=22ft.

also Should i keep that black insulation on the end of the run or does that not matter?